1. Field of the Invention
The present invention relates to an apparatus and method for separating the contaminants from a contaminated fluid mixture, particularly an apparatus and method for separating oil and other contaminants from water in a contaminated mixture.
2. General Background
Clean water is becoming scarce due to its wide use in many industries, including the oil and gas industry, and in pulp and paper mills, municipal waste treatment facilities, steel mills, food processing plants and electric generating plants. Polluted water, containing contaminating fluids, such as oil, and solid contaminants, is a by-product and ever-growing problem of these industries. In particular, the production of oil and gas wells and the refinement of these fluids produces contaminated wastewater. A need exists to clarify and recover the water from the contaminated wastewater.
Several devices have been proposed for recovering the water by clarifying and/or separating out the contaminants from the wastewater.
U.S. Pat. Nos. 5,407,584 and 5,300,222, both issued to applicant's assignee, and entitled "Water Clarification Method" and "Water Clarification Method And Apparatus", respectively, teach a method and apparatus for separating oil-gas vapors and solids from a liquid which has a separator vessel with a cyclonic flow chamber and a tangential inlet with a spiral preliminary separator to introduce the fluid and establish a swirling body of fluid. The cyclonic flow chamber has concentric shells positioned below the tangential inlet for discharging separated solids and further separating oil and water. The cyclonic flow chamber and the separator vessel wall form a fluid flow zone where eductors aerate the water and oil mixture, thereby separating them. A vertical outlet port discharges separated oil and gas from the upper portion of the cyclonic flow chamber to a fluid flow zone wherein the oil and gas are separated. The separated water, oil, go and solids are removed through discharge ports in the separator vessel.
U.S. Pat. No. 4,731,164 issued to W.R. WILLIAMSON and entitled "Multi-Stage Flash Evaporator" discloses a multi-flash evaporator wherein the fluid to be flashed is tangentially fed to each stage through an inlet which enters each stage about the midpoint of each stage.
The aforediscussed U.S. Pat. Nos. 5,407,584 and 5,300,222 are somewhat complex in design, having multiple separation stages with the separation method separating different contaminants at different stages.
The aforediscussed U.S. Pat. No. 4,731,164 is concerned with separating contaminated fluids through heat, not physical separation through turbulence.
Thus, a need exists for an apparatus and method for removing oil and solids from contaminated water which is simple in design, requiring fewer parts and/or stages than the prior art devices.
A need also exists for an apparatus and method with the above features that accomplish the above stated separation in one stage or fluid flow area.